In the last two decades, the automatic mechanization of the working of flat-stratified coal seams with 0-20 gon (0 to 18 degrees) dip and slightly inclined deposits with 20-40 gon (18 to 36 degrees) dip has led to outputs of up to 1500 t/h with mining ploughs in plough systems and of over 2600 t/h with shearers. Nowadays, the volume of coal which is worked underground stems more than 90% from flat or slightly inclined deposits, since with existing mining technology these can be worked considerably more economically than coal seams or other mineral seams in heavily inclined formation with more than 40 gon (36 degrees) dip, or in steep formation with 60 gon to 100 gon (54 to 90 degrees) dip.
For the working of coal in inclined formation, in particular in steep formation, mostly baseplate plough systems or portal-type plough systems have most recently been used, and DE 32 45 515 C2 describes by way of example a plough system for the working of steeply stratified coal seams with a dip of more than 60°. In this baseplate plough system for steep formation, the guide mechanism consists of a chain channel profiled roughly in a C-shape, in which the plough baseplate engages with a guide block.